The reproduction and development group of six laboratories are projects focused on analysis and definition of control mechanisms in reproduction and development. These include studies of hormones and aggression in mice and the role of pheromones in mammalian reproduction (Bronson), the control of RNA synthesis by steroid hormone (estradiol) and the mechanisms of steroid action in cytoplasm and nucleus of cells of target organs (rat uteri) (Hamilton). Forrest is characterizing and analyzing the function of repetitive and satellite DNA's and DNA dependent RNA polymerases during development, and studying the interaction of pteridines with chromatin, in the bug Oncopeltus and in Drosophila. Hardesty is identifying and characterizing substances that control initiation and synthesis of peptides, mostly in the cell-free rabbit reticulocyte system. He studies Met-tRNA hydrolase, an aminoacyl-tRNA synthetase complex, and a protein initiation factor. Menaker's group studies the roles of eyes, pineals, and extraretinal brain photoreceptors in control of circadian rhythms and annual reproductive cycles in birds and mammals. Jacobson's group analyzes the mechanisms by which embryos organize themselves, especially the localization of developmental information in Drosophila eggs, the determination of heart, eye, etc., in vertebrates, and the shaping of nervous system, the eye, and somites in amphibia and birds.